A number of systems and methods are known for spraying flowable coating materials onto surfaces such as walls, ceilings, and the like. Spray applicators for dispensing coating materials such as paint, drywall texture material, and stucco generally fall into this category. The present invention generally relates to such spray applicators, such as hopper gun applicators, that dispense discrete quantities of coating material.
The present invention is particularly suited to the dispensing of stucco material, and that application will be discussed herein in detail. As used herein, the term "stucco material" refers to spray surface coatings containing a hardenable base material and an aggregate such as sand, vermiculite, and/or perlite. Stucco material is normally, but not necessarily, a waterproof material that is applied to external wall surfaces. Stucco materials are often applied in a plurality of coats having a total thickness of at least one-eighth of an inch and normally in the range of one-half to three-quarters of an inch. Often, the stucco material is worked while it is wet to obtain a desired surface texture.
Stucco material is commonly available in one of two basic forms. Traditional stucco material comprises a dry cementitious base material (e.g. cement and lime) and sand and/or other aggregates. The dry material and aggregate material is mixed with water, applied to a surface to be coated, and allowed to set. Traditional stucco material is normally applied to a layer of wire mesh attached to the surface to be coated. Traditional stucco is built up in successive coats to the desired thickness and may be worked and painted for the desired aesthetic affect.
A more modern stucco material will be referred to herein as EIFS (Exterior Insulation and Finish Systems) stucco material. EIFS stucco material comprises an acrylic or latex base and aggregate such as sand, vermiculite, and/or perlite. EIFS stucco material is often applied to a foam layer attached to the surface to be coated. The foam layer provides insulation, while the EIFS stucco material forms both a protective, waterproof exterior surface and a desired aesthetic appearance (e.g., color, texture). The base coat normally forms the waterproof layer, while the top coat forms the aesthetic layer. Both of these basic types of stucco material are relatively viscous, and they both contain an often abrasive aggregate material.
Often, a stucco finish will become damaged. The need thus exists for convenient systems and methods for repairing either a traditional stucco finish or an EIFS stucco finish.